1. Presentation by Chris Austin
Photo by Sandy Redding

2. Searles Lake is an dry lake bed (playa) in an endorheic
basin located southwest of Death Valley and east of
Ridgecrest in the Mojave Desert.
Click here to view Searles Lake on Google Maps.

3. An endorheic basin is a terminal or closed basin, having no outflow to
another basin or the ocean. Water here can only leave by evaporation.
or seepage, thereby leaving salts and other dissolved minerals behind.
Click here to learn more about endorheic basins.

4. Searles Lake was one
of the Pleistocene-era
lakes, which were fed
by massive runoff
from the Sierra
Nevada mountains.
The water spilled into
a chain of inland seas.
Searles Lake was the
third in a chain of five
lakes that stretched
from Mono Lake to
Death Valley and
beyond.
To learn more about the
Pleistocene era, click here.

5. The lake bed has been commercially mined since John Searles
discovered borax here in 1862.

6. The lake bed is a resource
of sodium and potassium
minerals, yielding
1.7 million tons of
industrial minerals
annually, with total
mineral reserves
exceeding 4 million tons.

7. The lake bed is also used for evaporative salt extraction .
Photo by flickr photographer AlishaV.

8. The small town of Trona lies on the northwestern side of the lake bed.

9. The town was established in 1913 as a self-contained company town
to house the employees of the local mining operation. Mining is
still the main economic activity of the town today.

10. Soon after the town was built, a branch line was constructed
to connect Trona to the Southern Pacific line.

11. It is still in use today.
Photo by Sandy Redding.

12. The town was named after the mineral trona, which is an evaporite
mineral and the primary source of sodium carbonate, also known as
soda ash, in the U.S. Soda ash is a key ingredient in many household
products, and an important part of many industrial processes.
Click here to learn about soda ash.

13. The mineral extraction process uses a complex solution mining
technique that utilizes naturally occurring brines pumped from
wells of varying depth beneath the salt pan.

14. A network of production wells, injection wells, solar ponds and pipes
are used to transport the brine to the facilities for processing.

15. Every year, Trona hosts the Gem-O-Rama show, which draws
rockhounds from all over. It is the only time the public is allowed
on the lake bed to collect rocks.
Find out more about the Gem-O-Rama by clicking here:
http://www1.iwvisp.com/tronagemclub/SiteMap.htm
Photo by flickr photographer AlishaV.

16. The most interesting feature of the Searles Valley are the Trona
Pinnacles located at the south end of the dry lake bed.

17. The pinnacles are a popular set location. Over 30 film projects a year
are shot here, from sci-fi movies to car commercials to TV shows.
Photo by T. Hoffarth

18. Here, more than 500 spires of varying sizes and shapes, some as tall as
140 feet, rise from the dry lake bed.

19. The site is maintained by the Bureau of Land Management, and is
accessible by a 5 mile dirt road located just south of Trona.

20. The pinnacles are tufa formations which were formed over at least
three ice age periods. They are believed to be between 10,000 and
100,000 years old.

21. Tufa can only be formed underwater, which means these pinnacles
were once completely submerged.

22. Calcium-rich groundwater
bubbled up from underwater
springs and mixed with the
alkaline lake water to create
calcium carbonate, the main
component of tufa.

23. The tufa at the Trona Pinnacles is
primarily an algal tufa. Algae
aided tufa growth by removing
carbon dioxide from the water as
it photosynthesized, helping the
calcium carbonate precipitate.

24. The shapes of the tufa are dependent upon the size, flow & chemical
composition of the hot springs that formed them, as well as the spacing
of the springs and the depth of the water at the time they were forming.
Click here to learn more about tufa.

25.  Trona Pinnacles: the Bureau of Land Management website:
http://www.blm.gov/ca/st/en/fo/ridgecrest/trona.html
 Searles Valley Historical Society:
http://www1.iwvisp.com/svhs/mastersitemap.htm
 Searles Lake Gem & Mineral Society:
http://www1.iwvisp.com/tronagemclub/SiteMap.htm
 Trona, California: portrait of a mining town:
http://www.polarinertia.com/may04/trona01.htm
 View Searles Lake and Trona on a Google Map:
http://maps.google.com/maps/ms?hl=en&ie=UTF8&msa=0&msid=1044
56922237476241470.0004920dc8545f957a3cd&ll=35.680725,-
117.319565&spn=0.277759,0.521851&z=11

26.  The Trona Pinnacles, remembered:
http://www.high-desert-memories.com/pinnacles.html
 Trona’s Valley Wells, remembered:
http://www.high-desert-memories.com/tronapool.html
 How to do the Gem-O-Rama:
http://www.ehow.com/how_4551987_gemorama-trona-
california.html

27. Presentation by:
Chris Austin
Maven’s Manor
www.MavensManor.com
Photo by Sandy Redding